. >>> we now move to the chilling story of a 27-year-old man in maryland that police call a suspect in a series of mother-daughter murders. >> capturing jason thomas scott and cracking the case was quite a challenge for investigators near washington, d.c. pierre thomas reports. >> reporter: the horror began at this home on january 26th, 2009, as an intruder neutralized the alarm system and slipped in. karen lofton, a 45-year-old nurse, was fatally shot as she tried to hide in this corner. her 16-year-old daughter was repeatedly shot as she frantically dialed 911 from her bed. police were perplexed. the doors were locked. no signs of forced entry. neighbors were terrified. two months later, the bodies of dolores dewitt, 42, and her 20-year-old daughter, ebony, were found in a burning car less than a mile away from the loftons' home. another nurse and a daughter killed. >> i will tell you mr. scott presented us with a very challenging ability to identify him as a suspect. >> reporter: this man, jason thomas scott, was charged in the murders of the dewitts and the chief of police here is